Drifting and relief valve.



H. F. RlPKEN. DRIFTING AND RELIEF VALVE. A'LICATlON FlLD MAR-23|1918Pufoented' Oct. 8, 1918r mama . exhaust channel on that side.

^ nnrcn.

HUGO F. RIPXEN, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR OF ONE-HALF TOCHARLES A. MCCULLOCH, 0F MINNEAPOLIS, MINNESOTA.

nmrTINe Ann RELIEF VALVE.

Specification of Letters Fatentf utented @et sa 1918 Application filedMarch 23, 1918. Serial No. 224,198.

To all whom it may concern.' l

. Be it known that I, HUGO F. RIPKEN, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements in Driftingand Relief Valves, of which the following is a specification.

My invention relates to improvements in drifting and relief valves forreciprocating steam engines, and especially for those employed inrailway locomotives using superheated steam.

The present invention is an improvement to be applied in the driftingvalve shown in my pending application for Letters Patent on drifting andrelief valves, filed June 1o, 1916, serial No. 108,328.

It will be understood that when the throttle valve of an engine movingunder steam pressure, is closed to out oil' the steam supply from thecylinder the engine will drift for some time before it actually comes`to rest. In thus drifting, the piston will continue to reciprocate underthe inertia of the locomotive.

When, in an engine the live steam supply entering the cylinders is outoff, the pressure behind the advancing piston (during the drifting) isreduced to a degree which tends to or does'create a vacuum at thatpoint. This causes an inrush of air through the usual cylinder cocks andalso from the smoke box through the exhaust nozzle and exhaust chamberwhen'the piston valve in the steam chest has uncovered the port to theIn engines having superheating` equipment thecreation of a vacuum behindthe piston is very objectionable, the resulting inrush of air, gas andother foreign matter causing combustion and the destruction of thelubrication in the cylinder, thereby resu ting in undue friction andexcessive. wearing of parts.

The object of the present invention is to positively controlling themovement of the yalve piston and for controlling the'pressure above thepiston, when the throttle is closed.

Mo1e particularly the invention consists in the construction,combination and arrangement of parts hereinafter described and claimed.

In the accompanying drawings forming part of this specification,

Figure l is a vertical, longitudinal section through the middle of thecylinder and steam chest of a reciprocating' engine with my improvedvalve in elevation, and

Fig. 2 is a vertical section through the middle of. the valve alone.

In the drawings, rL-represents the cylinder 'of a reciprocating engine,B the piston working therein, and C the Steam chest in wliichworks avalve piston D, all of usual type.

The driftingvalve which is the subject of this invention `comprises acylindrical casing or valve body 2, the interior of which ais opent'ocommunication with one end `of the interior of the cylinder through theme dium of the threaded mipple at the lower extremity of the valve body,the interior of which leads into a duct 4 extending around a bushing atone end of the steam chest to the cylinder port 5 on that Side of thepiston B.

The compressed air or steam in that end of the cylinder will thus passthrough the duct l into the lower partof the valve casing, under thevalve, hereinafter described. l Y f Leading from the top of the valvecasing 2 to the main steam supply pi pe or conduit E and communicatingwith the interior thereof is an auxiliary steam supply 'pipe ficommunicating with the interior in the top of the casing 2, the casingbeing provided at one side, projecting laterally therefrom,

with a live steam inlet 7, which is open tol communication with the pipe7 which is f u the point where it joins the lower portion, provide in myprior invention, means lou.

-'a circular fiat seat or Shoulder 9, which seats on a cooperatingshoulder 9 in the casing.

The piston may therefore be termed a differential piston as it has a;top and bottom of different diameters and main and auxiliary bottomsurface. A plurality of oblong portsY l0 pierce the periphery of theupper portion ot the piston` suitable piston rings to prevent leakagebeing provided above and of live steam supshoulder 14 in the the valve.piston 8,

below the ports therete.

, A bushing 11 wherein the piston 8 slides,

4thereby forming the annular walled chaminlet 7, the inlet being berportion 'of the' open to communication with the interior of the supplypipe 7?. This inner wall of the inlet chamber portion is pierced by acircumferential row of ports 13, which are arranged to register with theports'l when the piston l8 is slid upward against the casing.

Leading downwardly from the annular Vchamber portion of the inlet, inthe casing y'wa-ll and opening into the interiorjot the casing at apoint above the shoulder 9 (whereon the piston normally rests) throughthe port guarded aga-inst leakage rings in the piston.

lt will be noted (Fig. 2) that. the Ap orts 10 and 13 are adequatelyprotected by piston lby suitable piston i rings to guard against undueleakage of steam :from the pipe .Opposite the port 15', piercing thewall of lthe casing at a point in the shoulder 9a is a vent 16 whichacts as an erhaust and may he open to the atmosphere, or be connectedwith the exhaust chamberas shown in Fig. 1.

ln operation, when the throttle valve, not shown is closed, the pressurein the conduit immediately thereafter falls or is reduced, while thepiston (lf ig. 1) will travel, (while the engine is drifting), to theright, compressing the gases before it, and producing a back pressure inthe cylinder, in the port 5, and in the vduct 4. This back pres-sure iscommunicated to the bottom f causing itr to loe lifted from its seat inthe casing and slide upwardlyl until it abuts against the shoulder Qt.When in this position, as hereinbefore stated, the ports and 13 are inperfect register, thereby establishing communicationv between theinterior of the pipe 7 and the interior of the casing. i

Live steam from pipe 7 will now pass (as Vindicated by `the arrowsFig. 1) through the inlet into the casing 2 above the valve piston andthrough the medium of pipe G and con' duit ll enter the steam chestlandcylinder, where it will prevent any vacuum forming tendency behind thepiston.

lllyhei'einbefore mentioned, prior invention, operated, generally up tothis point, as above described, but l have found by experiment that thepressure i thc conduit (when the throttle is closed) which iscounteracted only by the back pressure generated in the cylinder and thefriction of the parl(- ing rings (on the valve piston) and which, in myprior invention was solely relied upon t0 maintain the valupisto inoperating and immediatelyV ralliacent i .15 is a duct the port beingposition, was not adequate, to prevent a fluctuating movement of thevalve piston which lcaused the supply of steam admitted through theinlet 7 to be reduced to` such a degree as to render the pressure in thecylinder ina-dequate for drifting.

To prevent a' fluctuating movement of the valve, I provide the duct 15ahaving a port cessive conduit pressure on the top of the valve piston,thereby controlling movement of the piston. y

As the valve piston 8 is automatically raised, (by pressure generated inthe cylin-v der), it uncovers the port 15 to admit live steam to theannular cavity formed between the seat, 9 and its copcrating shoulder 9in the casing w(when the valve piston moved) the steam pressure in thecavity serving to regul'atethe pressurewhich causes the downwardmovement of the piston as will be hereinafter explained.

The vent 16 admit-s air to the cavity to prevent the creation of thevacuum therein (when the valve piston is raised) which would otherwisetend toy oppose-the back pressure generated in the cylinder. It alsoacts as a restricted, outlet for the inrushing steam, the vent 16 beingappreciably smaller than the inlet port' 15, resulting in backpressurein the cavity, whereby the piston is controlled to descend onlywhen there is execs sive steam pressure above it, which occurs when theengine .is drifting very slowly or actually comes to rest.

`When the engine comes to rest the valve piston descends, covering theports 10 to cut off the live steam supply and then covering the port 15from which point it will slowly descend, lridingion the air or steampocketed in the cavity which is now expelled through 11()l therestricted vent, 16 by the descending piston, whereafter the pistonvalve comes to rest on itsseat.

While I prefer the particular construction shown in the drawings, I wishit understood that. many Variations in the general structure may be madewithout departing from the general principle underlying my invention.

I claim:

1. In a reciprocating engine, the combination with the cylinder andsteam chest, of a drifting valve comprising an outer ycasing open tocommunication with the cylinder at 'one end and communicating with thesteam 125 chest at the o'her end, an annular-'ported steam inlet chamberin the casmg to admit live steam, a ported shdable valve piston in thrlcasing having a shoulder and adapted to register with its ports, theports in said an- Leens-1s nuler chamber but nori'nallyl covering thelatter and actuatable by the pressure in the cylinder when the engine isdrifting and the Vic main steam supply is cut oli', and a duct thecasing open to communication with said annular chamber at one end andopening at its other end against the sliding face of the poited valvepiston above said shoulder and rendered operative, when the valve pistonis actuated to uncover the ports in said annular chamber and saidopening of said duct to admit live steam into contact with a part of thepiston below7 said shoulder to'control live steam inlet to admit livesteam, a ported differential valve piston in the casing norinallycovering said live steamvinlet to liold the interior of thecasingabovethe piston closed to communication With the steam chesu andactuatable by pressure' in the cylinv der when the engine is driftingand the main steam supply is cut ofi', and having a main and auxiliarypressure receiving'. bottom s ur-' faceand a duct in the casing open tocom-' munication with said live steam inlet at one tion with saidauxiliary pressure receiving bottom surface at the otherend, but opened`to communicate therewith when said differentialv valve piston isactuated for the purpose set forth.

- 3. ln a reciprocating engine, the combination with the cylinder andsteam chest, of a drifting valve open to communication with the cylinderat one end and communicating with the steam chest at the vother end,said drifting valve comprising an outer casing having a differentialbore and an annularv ported live-steam inlet to admit live steam,

a. valve piston in the bore of the casing actuf atable by pressure inthe cylinder when the' engine is `driftiii and the main steam supply iscut off and normally holding the interior of the casing above the pistonclosed to communication With said annular ported live steamV inlet andaduct open to communication with the annular live steam inlet, and havinga port adjacent the point of differentiation in said bore and normallycovered by the valve piston and rendered effective when the valve pistonis actuated to admit live steam into the casing above the piston andsaid port is uncovered to admit live steam to completely surrounda partof Jsaid valve` piston to exert ,an 'upward pressure thereo 4. In 'areciprocating engine, the combina-- tion with the cylinder and steamchest,l 'of a drifting valve, comprising ,a valve casing open tocommunication with the cylinder at one end and the steam" chest at theother endl, said valve casing having a live steam inlet and an internalshoulder, a piston'having a peripheral seat adapted to engage saidshoulder and normally in engagement therewith 1 covering said live steaminlet, said piston being actuatable to disengage said' shoulder anduncover said live steam inlet by the pressure in the cylinder when the'engine is drifting and the main steam supply is cut off, a duct in thecasing open to communication with said live steam inlet and the interiorof thevalve casing adjacent and above said shoulder,- and a ventpiercing said shoulder and opening against said peripheral seat of thepiston when the latter is in engagement 4with said shoulder whereby whenthe piston. is Vactuated to uncover said live steam 4inletto admit livesteam into' the interior of the valve casing above the piston steamadmitted through the duct tothe underside of said peripheral seat toexert pressure thereon may escape lsaidvent and duct differentiating insize for the-purpose set forth. end and closed by the piston tocommunica`.`

5. Ina reciprocating engine, 'the combinaftion with the cylinder andsteam chest, of a Vand the steam chest at the other end, a movableported device fitted slidably in the casing and dividing the interiorthereof-` to pref vent conununicationdbetween said ends and actuatableby -thepressure in the cylinder when the engine is drifting and the mainsteam supply is cut olf, a ported live steam inlet/in the casing in thepath of said ported movable device and ther with when thelatter ismoved, a duct open to communication at one end with said adapted toregister live steam inlet, and means in the casing and said movabledevice cooperating when the latter is moved to further divide the in'-terior of the casing and to uncover the other end of .said duct intocommunication with the interior of the casing for the purpose set forth.l

In testimony whereof I aflix my signature in presence of two Witnesses.

HUGO F. RIPKEN, Witnesses: i

GEORGE VOELKER, FLORENCE WINKLER;

